The scanning tunneling microscope (STM) is an apparatus utilizing tunneling current generated by applying a bias voltage between a probe and a sample. The level of tunneling current is in reverse proportion to the distance between the probe and the sample. Accordingly, for instance, when the sample is scanned while adjusting their distance to provide a constant tunneling current, the fine surface shape of the sample can be determined from the displacement of the probe. Because the scanning tunneling microscope can observe atom arrangements and surface structures on the atom scale, it is used for the evaluation of semiconductor devices, the observation of biomolecules, etc. However, because observation using the scanning tunneling microscope needs extremely complicated operations such as the setting of a microscope at a measurable condition, the exchange of a deteriorated probe, etc., the scanning tunneling microscope is not suitable for treating large numbers of samples. It is thus used only for research, but not yet in industry.
JP2003-254886 A1 discloses a gas chromatograph scanning probe microscope comprising a scanning probe microscope comprising a means for evaporating and decomposing a sample by heating a portion of the sample to be observed at a tip end of a probe fixed to one end of a cantilever, and a gas pipe passing from a tip-end opening of the probe to the opening of the cantilever at the other end through the probe and the cantilever; and a gas chromatograph mass analyzer receiving a gas from the other-end opening of the cantilever through the gas pipe. Using this gas chromatograph scanning probe microscope, the sample can be evaporated to generate a gas, which is collected to analyze the composition of the sample. However, because the probe is contaminated after the analysis, the probe should be detached and washed. Accordingly, it is impossible to automatically conduct the analysis of pluralities of samples.
U.S. Pat. No. 5,166,520 B1 discloses a probe for a probe microscope, which has a tapered hollow shape for use in the scanning of sample surfaces in various technical fields. The hollow probe is mounted, for instance, to a free end of a cantilever. A cavity of the hollow probe is filled with a metal, a semiconductor, an electrolytic solution, etc. selected by taking interaction with a sample surface into consideration, and the filled material is connected to a conductor wire longitudinally extending in the cantilever. The hollow probe has an opening with a predetermined diameter at a tip end, so that the material charged into the hollow probe leaks. However, because only a material charged into the cavity of the hollow probe in advance can be leaked, it cannot be used while continuously supplying the desired sample.
Using the scanning tunneling microscope, the position of a probe can be controlled on the atom scale to depict a fine pattern. JP7-49352 A1 discloses a scanning tunneling microscope comprising a hollow probe for detecting tunneling current, a different material from the probe and filled in the probe, and a heater disposed near the probe. To depict a fine pattern by the scanning tunneling microscope described in JP7-49352A, a probe is moved by a function of the scanning tunneling microscope to a position at which atoms should attach, the different material in the probe is melted or softened by the heater to attach to the sample surface. However, what can be continuously attached to a sample by this microscope is only a material filled in advance. Accordingly, this microscope is not suitable for depicting a pattern with pluralities of materials. Although JP7-49352A describes that different materials filled in the probe are selectively melted or softened, the selective melting or softening of one material would be extremely difficult even if pluralities of materials were charged into the probe. Accordingly, to depict a pattern with pluralities of materials, they should practically be charged into the probe one after another, needing an extremely complicated operation.
Objects of the Invention
Accordingly, an object of the present invention is to provide a scanning probe microscope system capable of automatically treating pluralities of samples.